<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>解码字母到整数映射</title>
</head>
<body>
  <script>
    function fn(s) {
      let res = '', chars = 'abcdefghijklmnopqrstuvwxyz'
      for (let i = s.length - 1; i >= 0;) {
        if (s[i] === '#') {
          res = chars[s.substring(i - 2, i) - 1] + res
          i -= 3
        } else {
          res = chars[s[i] - 1] + res
          i -= 1
        }
      }
      return res
    }
    console.log(fn('10#11#12'))
  </script>
</body>
</html>